The present invention is directed to an underbelly or mid-mount mower for use in conjunction with a tractor and which is easily moveable between a mowing position and a blade accessible position that allows a user to easily perform mechanical work on the underside of the mower.
Self propelled mowers are generally either of the self-contained type where a mower is mounted directly on a tractor or the trail-behind type in which the mower is pulled by a tractor. Of the self-contained type, the mower is normally of two types which are forward deck mounted or underbelly mounted. Each type has its benefits and associated problems. Historically, one of the problems with the underbelly type is that, because the mower is mounted beneath the tractor, it is very difficult to get to the underside of the mower, especially the cutting blades, for repairs and the like without substantial disassembly of the mower.
In prior art underbelly mowers, an operator has often had to raise the tractor off the ground as they would a car, utilizing jacks, ramps or the like to the point where the underside of the mower is sufficiently raised for the operator to get under it with the blades generally in a horizontal plane, or the operator may raise the front end of the tractor as a unit until the tractor rests on its rear, where the blades are in a vertical plane, but the whole mower is also vertical. It is also common to have to completely disassemble the mower unit and remove it, in order to perform even minor repairs such as changing blades, cleaning or the like. None of these methods have worked very satisfactorily. Work on the mower is especially a problem when the operator is in the field and does not have independent jacks and other heavy tools to assist the operator. Commercial mower operators, who often must access the underside of the mower at least twice a day, often to change cutting blades, find such underbelly or mid mount mowers to be especially troublesome.
Therefore, it was found to be desirable to have a mower that provides the benefits of an underbelly mower, yet is relatively easy to convert to an accessible configuration by an unassisted operator. Furthermore, it was desired to provide such a mower that does not require cumbersome separate jacking or lifting equipment and that can easily be converted to the accessible configuration on the job by a single operator. Further, when the mower is raised, it is best to have the mower swing into a vertical rather than try to work on the mower a horizontal configuration, so that the operator does not have to crawl under the mower to work upon it. It is also desirable to provide an accessible configuration wherein the mower is stable.
In some embodiments it is also desirable to provide the operator with a mechanized assist apparatus that helps place the mower blades in a vertical plane wherein the assist apparatus mechanically rotates and raises portions of the device. Such assist apparatus includes electrically or hydraulically powered devices such as linear screws, hydraulic cylinders and the like or hand operated screws. As the tractor can include a frame that medially pivots under control of such an assist apparatus to reduce the required lifting as may be solid and require some raising to rotate a mowing deck to an access position thereof. When the frame pivots, an over center spring is preferentially used to urge the frame to both the access position of the mower and to the use position thereof. It is also preferable for the mower blades to be accessible without having to disassemble the drive belt.
Further, the mower deck must be adjustable in height. In many instances, this requires suspending the deck from the frame of the tractor with a complex mounting mechanism. Because the suspension of the deck undesirably allows the deck to swing backward during use, drag links are sometimes used to properly position the deck. However, drag links present additional problems to an already complex mounting system and it is desirable in some instances to provide pushes that mount on the frame and push the deck, but do not interfere with raising or lowering the deck.